Tried an FJR today. Really nice but my wrists hurt, I need to get more weight off. What is the biggest riser made in terms of height and back adjustment? Also do any allow change of the angle of the bars to come back?
Depends on whether it's a Gen I or II bike. Gen I's D&D's give about the max without replacing cables and brake lines. Gen II has a factory adjustment, or rather spendy aftermarket solutions like Heli's etc that often replace the entire top tree. Do a search for more info.
Yep! Google is your friend, for instance: risers site:fjrforum.com, or substitute any particular brand for the word "risers".
Manufacturer's websites should give you the information about the "change" their product makes. As Dave said, there is a difference between Gen I and Gen II, so we need that information to give you a better answer.
I put the Helibars on my Gen I after deciding that straight-up-only D&D risers weren't enough. I would probably consider mounting both of them at the same time (risers on risers) if it didn't mean I'd have to totally reconfigure or replace all the cables and hoses.
Helibars make a huge difference, even so, for my 5'8" frame.
For Gen1, there are also GenMar risers which allow changing the angle of the bars. Not sure how much of a rise they give, though. I myself have HeliBars... which set the bars up and back.